Convention glass melting and refining furnaces and forehearth constructions in general include combination melter and bushing constructions for melting pieces of prerefined glass. The molten glass is passed through a fiberizing bushing which contains orifice tips through which the molten glass flows to produce fibers of a given diameter. The bushing through which the fibers are drawn is generally located on the underside of the forehearth which is connected to the glass refining furnace.
In a typical melt operation, a suitable glass batch is fed to a large melting tank which is provided with a melting zone and a refining zone. The glass is melted within a melting tank by the application of a suitable heat source. After passage through the refiner, the melted glass is fed through a plurality of bushings that are connected to the bottom forehearth.
Large production of glass fibers require many melting tanks for supplying glass to a large number of bushings associated with the forehearth construction. Conventional melters and bushings employed for processing glass for forming filaments occupy considerable space, are costly to install, and often produce seeds which disrupt proper formation of the glass filaments.
In accordance with the present invention, considerable improvement is realized in glass filament production by replacing the conventional melt operation with a three stage process. Stage one includes dual melters to allow a higher throughput capability and glass composition change via mixing of the melt. Stage two comprises a feed bushing that is designed to accept feed from the dual melters. The feed bushing is provided with screens secured near the top thereof and located below the dual melters. The screens remove seeds and condition the glass melt as it passes to the third stage, i.e. delivery stage, which incorporates a diverter for directing the glass melt flow to the fiberizing bushings in the optimum location with all three units, i.e. the dual melters, feed bushing, and diverter itself, being firmly attached one to the other so that no glass leakage can occur between the adjacent units during the flow of glass from the melters to the bushing tips associated with the fiberizing bushing.